U.S. patent number 9,766,426 [Application Number 14/519,123] was granted by the patent office on 2017-09-19 for miniature lens driving apparatus.
This patent grant is currently assigned to Summing Technologies (HK) Limited. The grantee listed for this patent is Sunming Technologies (HK) Limited. Invention is credited to Sio Kuan Lam.
United States Patent |
9,766,426 |
Lam |
September 19, 2017 |
**Please see images for:
( Certificate of Correction ) ** |
Miniature lens driving apparatus
Abstract
A miniature lens driving apparatus includes plurality of wires,
an optical image stabilizing (OIS) mechanism having a lens holder,
at least one magnet, and a plurality of coils; and an autofocus
(AF) mechanism having an AF moving platform movable along an
optical axis, at least one coil, and at least one magnet; wherein
the said plurality of coils of the OIS mechanism operatively
associates with the said at least one magnet of the OIS mechanism
to move the said lens holder of the OIS mechanism along a direction
substantially perpendicular to the optical axis; wherein the said
at least one coil of the AF mechanism operatively associates with
the said at least one magnet of the AF mechanism to move the said
AF moving platform along the optical axis.
Inventors: |
Lam; Sio Kuan (Hong Kong,
HK) |
Applicant: |
Name |
City |
State |
Country |
Type |
Sunming Technologies (HK) Limited |
Hong Kong |
N/A |
HK |
|
|
Assignee: |
Summing Technologies (HK)
Limited (Hong Kong, HK)
|
Family
ID: |
52870837 |
Appl.
No.: |
14/519,123 |
Filed: |
October 20, 2014 |
Prior Publication Data
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Document
Identifier |
Publication Date |
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US 20160109681 A1 |
Apr 21, 2016 |
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Current U.S.
Class: |
1/1 |
Current CPC
Class: |
G02B
7/28 (20130101); G02B 27/646 (20130101); G03B
13/36 (20130101); G02B 7/102 (20130101); G02B
7/09 (20130101); G02B 7/026 (20130101) |
Current International
Class: |
G02B
7/10 (20060101); G02B 27/64 (20060101); G03B
13/36 (20060101); G02B 7/28 (20060101); G02B
7/02 (20060101); G02B 7/09 (20060101) |
Field of
Search: |
;396/55 |
References Cited
[Referenced By]
U.S. Patent Documents
Foreign Patent Documents
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103969916 |
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Aug 2014 |
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CN |
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0867742 |
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Sep 1998 |
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EP |
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H04219709 |
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Aug 1992 |
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JP |
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20140098211 |
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Aug 2014 |
|
KR |
|
Other References
Partial European Search Report of counterpart European Patent
Application No. 15163977.0 issued on Mar. 7, 2016. cited by
applicant.
|
Primary Examiner: Laballe; Clayton E
Assistant Examiner: Hancock; Dennis
Claims
What is claimed is:
1. A miniature lens driving apparatus comprising: (a) a plurality
of wires; (b) an optical image stabilizing (OIS) mechanism having a
lens holder, at least one magnet, and a plurality of coils; wherein
the said plurality of coils of the OIS mechanism operatively
associates with the said at least one magnet of the OIS mechanism
to move the said lens holder of the OIS mechanism along a direction
substantially perpendicular to an optical axis; and (c) autofocus
(AF) mechanism having an AF moving platform movable along the
optical axis, at least one coil, and at least one magnet; wherein
the said at least one coil of the AF mechanism operatively
associates with the said at least one magnet of the AF mechanism to
move the said AF moving platform along the optical axis; (d)
wherein one ends of the plurality of wires are directly connected
to the said lens holder of the OIS mechanism while another ends of
the plurality of wires are directly connected to the AF moving
platform of the AF mechanism.
2. The lens driving apparatus as claimed in claim 1, wherein said
AF mechanism further comprises: (a) at least one guiding mechanism;
(b) wherein the said guiding mechanism includes a stationary guide
member and a slidable guide member; and (c) wherein the stationary
guide member is firmly mounted on a base while the slidable guide
member is firmly mounted on the AF moving platform.
3. The lens driving apparatus as claimed in claim 2, wherein the
said guiding mechanism is selected from the group consisting of
guiding shafts, V-shape grooves, dovetail-shaped grooves, C-shaped
grooves, guiding planes, guiding holes and guiding rings.
4. The lens driving apparatus as claimed in claim 2, further
comprising a stiffening member connected to the slidable guide
member.
5. The lens driving apparatus as claimed in claim 4, wherein a
viscous liquid is provided in a gap between the stiffening member
and the lens holder, and/or a gap between the lens holder and the
moving platform.
6. The lens driving apparatus as claimed in claim 5, wherein
opposing surfaces of the stiffening member and the lens holder,
and/or opposing surfaces of the lens holder and the moving platform
are formed with a plurality of pits for receiving therein the
viscous liquid.
7. The lens driving apparatus as claimed in claim 1, wherein the
OIS mechanism further comprises a wire coupling member attached to
the lens holder, and wherein one end of each wire is coupled to the
wire coupling member.
8. The lens driving apparatus as claimed in claim 7, wherein the
wire coupling member is in the form of a printed circuit board with
conductive traces and bonding pads provided thereon.
9. The lens driving apparatus as claimed in claim 7, wherein the
wire coupling member is made of plastics, polymers, metal, ceramic,
or a composite material made of plastic, polymers, metal, or
ceramic.
10. The lens driving apparatus as claimed in claim 7, wherein the
wire coupling member is integrated into the lens holder.
11. The lens driving apparatus as claimed in claim 1, wherein the
AF moving platform further comprises a wire coupling member, and
wherein one end of each wire is coupled to the wire coupling
member.
12. The lens driving apparatus as claimed in claim 11, wherein the
wire coupling member is in the form of a printed circuit board with
conductive traces and bonding pads provided thereon.
13. The lens driving apparatus as claimed in claim 1, wherein the
plurality of wires is selected from the group consisting of metal
wire, enamel metal wire, metal-clad metal wire, metal-clad plastic
wire and combinations thereof.
14. The lens driving apparatus as claimed in claim 1, wherein the
plurality of wires comprises materials selected from the group
consisting of conductive materials, non-conductive materials,
polymeric materials, plastics, rubbers and organic fibers.
15. The lens driving apparatus as claimed in claim 1, wherein the
said AF mechanism further comprises a printed circuit board or
flexible printed circuit board to provide electric connection.
16. The lens driving apparatus as claimed in claim 1, wherein the
AF mechanism and/or the OIS mechanism further comprises at least
one Hall sensor or position encoder to sense position of a
lens.
17. The lens driving apparatus as claimed in claim 1, wherein the
AF mechanism comprises at least one spring with one end connected
to a base of the AF mechanism and the other end connected to the AF
moving platform.
18. The lens driving apparatus as claimed in claim 17, wherein the
spring is selected from the group consisting of leaf spring, helix
spring and elastic film.
19. The lens driving apparatus as claimed in claim 18, further
comprising at least one Hall sensor or position encoder to sense
position of a lens.
20. An electronic image-capturing device comprising the lens
driving apparatus claimed in claim 1.
Description
FIELD OF THE TECHNOLOGY
The present application relates generally to a lens driving
apparatus which may be integrated within a compact camera module
used for portable electronic devices.
BACKGROUND
Compact camera module has been widely adopted in many types of
portable electronic device such as smart phone. Many sophisticated
camera functions have been integrated into compact camera module,
such as autofocus. Recently, the market is requesting the camera
module to equip with optical image stabilization function. This in
turn requests to have a miniature lens driving apparatus which is
capable of moving the imaging lens along X, Y, and Z
directions.
SUMMARY
According to one aspect, there is provided a miniature lens driving
apparatus including a plurality of wires; an optical image
stabilizing (OIS) mechanism having a lens holder, at least one
magnet, and a plurality of coils; and an autofocus (AF) mechanism
having an AF moving platform movable along the optical axis, at
least one coil, and at least one magnet. The plurality of coils of
the OIS mechanism operatively associates with the at least one
magnet of the OIS mechanism to move the lens holder along a
direction substantially perpendicular to an optical axis; and the
at least one coil of the AF mechanism operatively associates with
the at least one magnet of the AF mechanism to move the AF moving
platform along the optical axis. The lens holder of the OIS
mechanism is coupled with the AF moving platform via the plurality
of wires directly or indirectly.
The AF mechanism may further include at least one guiding mechanism
having a stationary guide member and a slidable guide member. The
stationary guide member is firmly mounted on the base while the
slidable guide member is firmly mounted on the AF moving platform.
The guiding mechanism may be in the form of guiding shafts, V-shape
grooves, dovetail-shaped grooves, C-shaped grooves, guiding planes,
guiding holes or guiding rings.
The OIS mechanism may further include a wire coupling member
attached to the lens holder, and wherein one end of each wire is
coupled to the wire coupling member. In one embodiment, the wire
coupling member is in the form of a printed circuit board with
conductive traces and bonding pads provided thereon.
The AF moving platform may further include a wire coupling member,
and wherein one end of each wire is coupled to the wire coupling
member. In one embodiment, the wire coupling member is in the form
of a printed circuit board with conductive traces and bonding pads
provided thereon.
The plurality of wires may be in the form of metal wire, enamel
metal wire, metal-clad metal wire, metal-clad plastic wire or
combinations thereof. The plurality of wires may be made of
conductive materials, non-conductive materials, polymeric
materials, plastics, rubbers or organic fibers.
The AF mechanism may further include a printed circuit board or
flexible printed circuit board to provide electric connection.
In one embodiment, the lens driving apparatus may further include a
stiffening member connected to the slidable guide member. A viscous
liquid may be provided in a gap between the stiffening member and
the lens holder, and/or a gap between the lens holder and the
moving platform. Opposing surfaces of the stiffening member and the
lens holder, and/or opposing surfaces of the lens holder and the
moving platform can be formed with a plurality of pits for
receiving therein the viscous liquid.
In one embodiment, the AF mechanism and/or the OIS mechanism may
further include at least one Hall sensor or position encoder to
sense position of a lens.
In one embodiment, the AF mechanism may include at least one spring
with one end connected to a base of the AF mechanism and the other
end connected to the AF moving platform. The spring may be in the
form of a leaf spring, helix spring or elastic film.
According to another aspect, there is provided an electronic
image-capturing device, such as mobile phones, cameras, etc., which
includes the lens driving apparatus disclosed in the present
application.
Although the miniature lens driving apparatus is shown and
described with respect to certain embodiments, it is obvious that
equivalents and modifications will occur to others skilled in the
art upon the reading and understanding of the specification. The
miniature lens driving apparatus in the present application
includes all such equivalents and modifications, and is limited
only by the scope of the claims.
BRIEF DESCRIPTION OF THE DRAWINGS
Specific embodiments of the miniature lens driving apparatus will
now be described by way of example with reference to the
accompanying drawings wherein:
FIG. 1a is a perspective view of a miniature lens driving apparatus
according to an embodiment thereof.
FIG. 1b is a cutaway view of the miniature lens driving apparatus
of FIG. 1a.
FIG. 1c is exploded view of the miniature lens driving apparatus
according to an embodiment thereof.
FIG. 1d is a perspective view of a miniature lens driving apparatus
according to another embodiment thereof.
FIG. 1e is exploded view of the miniature lens driving apparatus of
FIG. 1d.
FIG. 2a is a perspective view of the base with the printed circuit
board, the AF coil, a slidable platform being slidably engaged with
the base, and a plurality of magnets provided on the slidable
platform.
FIG. 2b is a perspective view similar to that in FIG. 2a showing
the sliding direction of the moving platform.
FIGS. 3a-d show different guiding mechanisms.
FIG. 4a is a cross sectional view of the miniature lens driving
apparatus according to an embodiment thereof.
FIG. 4b is an enlarged cross sectional view of a section of the
miniature lens driving apparatus according to an embodiment
thereof.
FIG. 5a is a perspective view of the wire coupling disc being
mounted on the lens holder of the miniature lens driving apparatus
according to an embodiment thereof.
FIG. 5b is an enlarged perspective view of the wire coupling disc
being connected to the wire of the miniature lens driving apparatus
according to an embodiment thereof.
FIG. 5c is a top view of the wire coupling disc being provided
thereon with conductive traces and bonding pads for wires according
to an embodiment thereof.
FIG. 6a is side view of a wire of the miniature lens driving
apparatus according to an embodiment thereof.
FIG. 6b is a cross sectional view of the wire according to a first
embodiment thereof.
FIG. 6c is a cross sectional view of the wire according to a second
embodiment thereof.
FIG. 6d is a cross sectional view of the wire according to a third
embodiment thereof.
FIG. 7a is a perspective view of a base of the miniature lens
driving apparatus according to an embodiment thereof.
FIG. 7b is a bottom perspective view of a printed circuit board of
the miniature lens driving apparatus according to an embodiment
thereof.
FIG. 7c is a perspective view of the base with the printed circuit
board being mounted thereon.
FIG. 7d is a perspective view of the base with the printed circuit
board and an AF coil 32 being mounted thereon.
FIG. 7e is a perspective view of another embodiment of the
base.
FIG. 8a is a perspective view of the stiffener being mounted on the
optical image stabilizing mechanism of the miniature lens driving
apparatus according to an embodiment thereof.
FIG. 8b is a cross sectional view of the optical image stabilizing
mechanism and the application of a viscous liquid according to an
embodiment thereof.
FIG. 8c is a cross sectional view of the optical image stabilizing
mechanism and the application of a viscous liquid according to
another embodiment thereof.
FIG. 8d is a top view of the optical image stabilizing mechanism of
the miniature lens driving apparatus according to an embodiment
thereof.
FIG. 8e is a cross sectional view taken along line A-A in FIG. 8d
shows a plurality of pits and the application of the viscous liquid
in the miniature lens driving apparatus according to an embodiment
thereof.
FIG. 9a is a perspective view of a miniature lens driving apparatus
according to another embodiment thereof.
FIGS. 9b-9e show different embodiments of a leaf spring.
FIGS. 9f and 9g are enlarged perspective views of the wires of the
miniature lens driving apparatus shown in FIG. 9a.
FIG. 9h is an exploded view of an AF moving platform according to
another embodiment thereof.
FIG. 9i is a perspective view of the AF moving platform shown in
FIG. 9f.
DETAILED DESCRIPTION
In the following detailed description, numerous specific details
are set forth to provide a thorough understanding of claimed
subject matter. However, it will be understood by those skilled in
the art that claimed subject matter may be practiced without these
specific. In other instances, methods, apparatuses, or systems that
would be known by one of ordinary skill have not been described in
detail so as not to obscure claimed subject matter.
Reference throughout this specification to "one embodiment" or "an
embodiment" may mean that a particular feature, structure, or
characteristic described in connection with a particularly
embodiment may be included in at least one embodiment of claimed
subject matter. Thus, appearances of the phrase "in one embodiment"
or "an embodiment" in various places throughout this specification
are not necessarily intended to refer to the same embodiment or to
any one particular embodiment described. Furthermore, it is to be
understood that particular features, structures, or characteristics
described may be combined in various ways in one or more
embodiments. In general, of course, these and other issues may vary
with the particular context of usage. Therefore, the particular
context of the description or the usage of these terms may provide
helpful guidance regarding inferences to be drawn for that
context.
Likewise, the terms, "and", "and/or," and "or" as used herein may
include a variety of meanings that also is expected to depend at
least in part upon the context in which such terms are used.
Typically, "or" as well as "and/or" if used to associate a list,
such as A, B or C, is intended to mean A, B, and C, here used in
the inclusive sense, as well as A, B or C, here used in the
exclusive sense. In addition, the term "one or more" as used herein
may be used to describe any feature, structure, or characteristic
in the singular or may be used to describe some combination of
features, structures, or characteristics. Though, it should be
noted that this is merely an illustrative example and claimed
subject matter is not limited to this example.
As used to describe such embodiments, terms "above", "below",
"upper", "lower", and "side" describes positions relative to an
optical axis of such a compact imaging module. In particular,
"above" and "below" refer to positions along an optical axis,
wherein "above" refers to one side of an element and "below" refers
to an opposite side of the element. Relative to such an "above" and
"below", "side" refers to a side of an element that is displaced
from an optical axis, such as the periphery of a lens, for example.
Further, it is under stood that such terms do not necessarily refer
to a direction defined by gravity or any other particular
orientation. Instead, such terms are merely used to identify one
portion versus another portion. Accordingly, "upper" and "lower"
may be equivalently interchanged with "top" and "bottom", "first"
and "second", "right" and "left", and so on.
It should be noted that throughout the specification and claims
herein, when one element is said to be "coupled" or "connected" to
another, this does not necessarily mean that one element is
fastened, secured, or otherwise attached to another element.
Instead, the term "coupled" or "connected" means that one element
is either connected directly or indirectly to another element or is
in mechanical or electrical communication with another element.
It should be noted that throughout the specification and claims
herein, the term "wire" is defined as a thin length of a material.
It can also be a thread of metal, polymer, cotton, hemp, or other
material twisted together to form a thin length or line. It is used
as a synonym of string, rope, cord, thread, and line.
It should be understood that the present application is not limited
to the preferred embodiments described hereinabove and, needless to
say, a variety of modifications or variations may be made without
departing from the scope of the protection defined herein.
A miniature lens driving apparatus 10 may include a plurality of
wires 18, an optical image stabilizing (OIS) mechanism 16 having a
lens holder 52, and an autofocus (AF) mechanism 12 having an AF
moving platform 14; wherein the said OIS mechanism 16 is capable of
moving the lens holder 52 along a direction substantially
perpendicular to the optical axis X; and the said AF mechanism 12
is capable of moving the AF moving platform 14 along the optical
axis X; wherein the said lens holder 52 of OIS mechanism 16 can be
coupled to the AF moving platform 14 via the plurality of wires 18.
Defined hereinafter, the said AF moving platform 14 is referring to
the aggregation of all moving parts of AF mechanism 12, but
excluding the coil, magnet, and spring.
FIGS. 1a-1c shows one of the embodiments of the above said
miniature lens driving apparatus 10. The miniature lens driving
apparatus 10 may include an upper casing (top cover) 22, a
plurality of wires 18, and an autofocus (AF) mechanism 12, which
may include an AF moving platform 14 movable along an optical axis
X, a bottom casing 24, at least one coil 32, and at least one
magnet 34; wherein the AF moving platform 14 may include a
platform, and a wire coupling member 156, which is used to connect
the AF moving platform 14 to the lens holder 52 of OIS mechanism 16
via the plurality of wires 18. The wire coupling member 156 can be
mechanically firmly attached to a lower end of the said platform.
In another embodiment, the wire coupling member 156 can be
integrated into the said platform and become an undetectable part
of the said platform. In that case, AF moving platform 14 may
include the said platform only. In other words, the plurality of
wires 18 can be directly connected to the AF moving platform 14 in
another embodiment. The bottom casing 24 is also named as base. The
said coil 32 of the AF mechanism 12 is named herein as AF coil 32.
The AF coil 32 can be mechanically firmly mounted on the base 24.
The leads of AF coil 32 can be directly or indirectly electrically
connected to the electrodes 126. At least one magnet 34 is mounted
on the AF moving platform 14 and moving together with the AF moving
platform 14 along the optical axis. The said at least one AF coil
32 operatively associates with at least one magnet 34 to drive the
AF moving platform 14 and at least one magnet 34 to move along the
optical axis. In another embodiment, the said at least one magnet
34 may be mounted on the base 24 while the said at least one AF
coil 32 may be mounted on the AF moving platform 14 and moving
together with the AF moving platform along the optical axis.
In the above said miniature lens driving apparatus, the above said
AF mechanism may further include a plurality of guiding mechanisms
used to guide the AF moving platform moving along the optical axis;
wherein the guiding mechanism may comprise a stationary guide
member and a slidably guide member installed onto the base and AF
moving platform respectively. As shown in FIGS. 2a and 2b of the
present embodiment, a plurality of stationary guide members 42 and
a plurality of slidable guide members 44 can be installed on the
corner areas of the base 24 and AF moving platform 14 respectively
(FIGS. 2a and 2b). In some other embodiments, the guide members 42
and 44 may be installed on the other area of base 24 and AF moving
platform 14. The AF moving platform 14 may be slidably engaging
with the base 24 via the guide members 42, 44, as shown in FIGS. 2a
and 2b. In the present embodiment, the stationary guide members 42
may be in the form of four blocks extending from the corner areas
of the base 24. Each block may contain a flat surface or plane
parallel to the optical axis X which may be designed to be the
normal direction of the base 24. The guiding function is achieved
by sliding of the plane of slidably guide member on the plane of
stationary guide member. However, the guiding direction of such
guiding mechanism is two dimensional, which means the sliding
direction may not align with the optical axis. Therefore, four
guiding mechanisms are installed on the AF mechanism, which is four
pairs of stationary-slidably guide members are installed on the
corner area of the base and AF moving platform respectively. Every
two planes of two stationary-slidably pairs can be pairing together
to limit the AF moving platform 14 to move along the respective
diagonal direction perpendicular to optical axis X. Therefore, the
overall result of these four pairs of guide members 42 and 44 is
that the AF moving platform 14 can only move along the optical axis
X. Therefore, in the present embodiments, four pairs of guiding
mechanism are necessary.
FIGS. 3a-d shows some other embodiments of the guiding mechanisms.
FIG. 3a shows a guiding shaft-hole type guiding mechanism 142, 144.
FIG. 3b shows a C-curve surface mating type guiding mechanism 242,
244. FIG. 3c shows a V-groove type guiding mechanism 342, 344. FIG.
3d shows a dovetail-groove type guiding mechanism 442, 444.
Obviously, the guide members 42, 44 may be in the form of various
means and shapes to mate with the stationary member 42 on the base.
Such various means and shapes may include but not limited to
guiding shafts, V-shaped grooves, dovetail-shaped grooves, guiding
planes, guiding holes, guiding rings, etc. For one skill in the art
can easily realize many other guiding mechanisms, such as ring
type, slot type, ball type, and etc. Needless to say, all these
variation of guiding mechanism do not depart from the scope of the
protection defined herein. Furthermore, it is also obvious that for
other type of guiding mechanisms, it is not necessary to use four
pairs of guiding mechanism. Drawing four shafts or guiding
mechanisms in FIGS. 3a-d are just purely for the symmetric
arrangement of the shafts on the rectangular base 24. Needless to
say, using 1, 2, or 3 shafts or even more shafts in the
implementation does not depart from the scope of the protection
defined herein.
Moreover, in some embodiments, lubricant, oil, grease, or liquid
(such as water) can be applied to the contact surfaces or planes of
the four pairs of guide members 42 and 44 to reduce the friction
between the base 24 and the AF moving platform 14.
In the above said miniature lens driving apparatus, the above said
AF mechanism may further include a printed circuit board (PCB) or
flexible printed circuit board (fPCB) in some other embodiments
(FIGS. 1d and 1e). In such embodiments, the AF coil 32 may be
mechanically firmly mounted on and electrically connected to the
printed circuit board 26 which may be firmly mounted on the base 24
(FIGS. 7c and 7d). PCB 26 has electrodes 27 which are used to
provide electrical contact with the outside world. It should be
noted that the fPCB or PCB shown in FIGS. 1d-e and 7c-d is purely
for conceptual illustration purpose. Needless to say, the change of
shape and/or circuitry of fPCB or PCB do not depart from the scope
of protection defined herein.
In the above said AF mechanism of the said miniature lens driving
apparatus, the magnets 34 may be firmly attached to the peripheral
areas of the AF moving platform 14 and movable together with the AF
moving platform 14. In some other embodiments, the magnets 34 can
be mounted on the corner area of the AF moving platform. Needless
to say, the magnets can also be mounted on the base or a yoke
mounted on the base. The magnetization directions M (FIG. 2a) of
the magnets 34 are all lying in a plane which is substantially
perpendicular to the optical axis X. Or in other words, the
magnetization directions M of the magnets 34 are all lying in a
plane which is substantially parallel to the surface of the AF
moving platform 14. Furthermore, the magnetization directions M of
the magnets 34 are all either pointing inwards or outwards. The AF
moving platform 14 can be moved in an optical axis direction S1
(FIG. 2b). In another embodiment, the AF coil 32 may be attached to
the AF moving platform 14 while the magnets 34 may be attached to
the base 24.
In some embodiments, the base 24 may be integrally formed with
slots 23 for receiving therein electrodes extending from OIS coils
54 (FIG. 7e) of the OIS mechanism 16. Electrodes 25 may be mounted
in the base 24 for electrical contact with the outside world.
The above said miniature lens driving apparatus may further include
an OIS mechanism 16 as shown in FIG. 1c, which may include a lens
holder 52, a wire coupling member 56, at least one magnet 34, and a
plurality of coils 54. The lens holder 52 of OIS mechanism 16 may
be connected to the AF moving platform of the AF mechanism 12 via a
plurality of wires 18. In the present embodiment, a wire coupling
member is mechanically firmly attached to the upper portion of the
said lens holder 52. A plurality of wires is connected to the lens
holder via this wire coupling member. In another embodiment, the
wire coupling member is integrated into the lens holder and become
an undetectable part of the lens holder. In the other words, a
plurality of wires is directly connected to the lens holder in
another embodiment. A plurality of coils is firmly mounted on the
lens holder and operatively associates with the said at least one
magnet mounted on the AF moving platform to drive the lens holder
moving along a direction substantially perpendicular to the optical
axis.
FIG. 4a shows a cross sectional view of the assembly of present
embodiment and FIG. 4b is an enlarged sectional view of the
magnet-coils structure or the electromagnetic force generators of
the FIG. 4a. In the present embodiment, the OIS mechanism 16 and AF
mechanism 12 may be sharing the same set of magnets 34. The OIS and
AF mechanisms are utilizing the magnetic field on the upper and
lower side of the same magnet respectively. Moreover, the magnets
34 can be mounted on the AF moving platform 14 and the
magnetization directions M of the magnets 34 may be all lying in
the same plane perpendicular to the optical axis X in the present
embodiment. The magnetization directions M of the magnets 34 may be
all either pointing inwards or outwards. When the AF moving
platform 14 is locating at its lowest extreme of its sliding range,
the magnets 34 may be sitting on top of the AF coil 32 or a tiny
gap may exist between the magnets 34 and AF coil 32. When an
electric current is applied to the AF coil 32, an electromagnetic
force F1 is generated to drive the AF moving platform 14 to move
along the optical axis X for autofocusing.
The OIS coils 54 may be firmly mounted on the lens holder 52 which
in turn may be mounted on the AF moving platform 14 in such a way
that the OIS coils 54 are disposed adjacent to the magnets 34 used
for autofocus function. When an electric current is applied to the
OIS coils 54, the OIS coils 54 will generate an electromagnetic
field which in turn interacts with the magnetic field F of the
magnets 34 and a push/pull force F2 is thus generated. Limited by
wires 18, the so-generated push/pull force F2 will drive the lens
holder 52 to move/swing along a plane substantially perpendicular
to the optical axis X in a horizontal direction S2 for image
stabilization. Generally, a small gap may exist between the magnets
34 and the OIS coils 54 so that there will be no friction between
the AF moving platform 14 and the lens holder 52. However, in some
embodiments the lens holder 52 is in direct physical contact with
the AF moving platform 14. No gap is left in between. In such
embodiment, the OIS actuators have to be powerful enough to move
the lens holder. In some other embodiments, lubricant, oil, grease,
or liquid (such as water) may be applied to the contact interfaces
between AF moving platform 14 and lens holder 52 to reduce the
friction.
As described in the above, the OIS mechanism 16 and AF mechanism 12
may be sharing the same set of magnets 34. The OIS and AF
mechanisms are utilizing the magnetic field on the upper and lower
side of the same magnet respectively. However, in some other
embodiments, OIS and AF mechanisms may have their own magnet and
either magnet of OIS mechanism or AF mechanism are all mounted on
the AF moving platform together. In other embodiments, the magnets
used for OIS may be mounted on the other location of the said
miniature lens driving apparatus, but not on AF moving platform. In
some embodiments, the upper casing or top cover may be made of
magnetic conductive material and used as yoke to confine the
spatial magnetic field distribution.
FIGS. 5a-5c show more detail about the wire coupling member of OIS
mechanism. The wires 18 can be connected to the lens holder 52 via
the wire coupling member 56 as illustrated in the present
embodiment. In some other embodiments, the wire coupling member 56
may be integrated with the lens holder 52 as a part of the lens
holder 52. Or in other words, in some other embodiments, the wires
18 are directly connected to the lens holder 52. In present
embodiment, the first or lower ends of the wires 18 can be
connected to the AF moving platform 14 and the second or upper ends
of the wires 18 can be connected to the lens holder 52. In some
other embodiments, the lower ends of the wires 18 can be connected
to another wire coupling member, which can be in turn connected to
the AF moving platform 14.
The wire coupling member 56 is not necessary circular or in the
shape of a disc, as shown in the illustrated embodiment. It can
take any shape as long as it will not jeopardize the lens holder 52
movement and/or the AF platform 14 movement. The wire coupling
member 56 may be made of plastics, polymers, metal, ceramic, or
composite material made of plastic, polymers, metal, and/or
ceramic. The wire coupling member 56 may also be made of the same
material as the lens holder 52. In another embodiment, the wire
coupling member 56 may be integrated into the lens holder 52 as a
part of lens holder 52. In the present embodiment, the wire
coupling member 56 may be attached firmly to the lens holder 52 by
adhesives or some kinds of physical or chemical bonding method. The
plurality of wires 18 may be connected to the wire coupling member
56 by adhesives or soldering 58 at a wire-disc connection point
57.
In another embodiment shown in FIG. 5b, the wire coupling member 56
may be in the form of a printed circuit board which has circuitry
to provide electrical connections between coil leads and wires. In
another embodiment, conductive traces 62, conductive wires,
circuitry, channels, or paths are embedded into or printed onto or
mounted on the wire coupling member 56 to provide an electrical
connection means between the plurality of wires 18 and the OIS
coils 54. Bonding pads 60 for wires and bonding pads 61 for coil
leads may be provided on the printed circuit board. Although FIGS.
5a-c shows how the second or upper ends of the wires 18 are
connected to the lens holder 52, all the methods or means provided
above can all be applied to the first and lower ends of the wires
18 for connection to the AF moving platform 14. Needless to say, it
will be understood by those skilled in the art that the above
mentioned methods or means can all be applied to the AF moving
platform 14 without these specifics.
The wires 18 (FIGS. 6a-6d) may be using conductive materials,
including but not limited to metal wires, enamel insulated wires,
or other types of complex wires, such as wires 18' having a central
metal wire 181 and an outer insulated layer 182 (FIG. 6c), and wire
18'' having an insulated core 183 and an outer metal or conductive
layer 184 (FIG. 6d). In another embodiment, the wires 18 may be
using non-conductive materials, polymeric materials, plastics,
rubbers, organics fibers, etc. The plurality of wires 18 may
include metal wire, enamel metal wire, metal-clad metal wire,
metal-clad plastic wire and a combination thereof.
In another embodiment, a Hall sensor or position encoder 28 can be
either directly mounted on the printed circuit board 26 (FIG. 7b)
or the base 24 (FIG. 7a). In some other embodiments, flexible
printed circuit board (fPCB) may be used to replace the printed
circuit board 26. Moreover, in some other embodiments, the fPCB or
PCB can be removed and the coil 32 may be directly mounted on the
base 24 and electrically connected to the electrodes as shown in
FIG. 7e. In some other embodiments, Hall sensor or position encoder
can be mounted on the lens holder of OIS mechanism, or other
locations to measure the lens position of OIS. Therefore, in
general, a miniature lens driving apparatus may include a plurality
of wires, an OIS mechanism having a lens holder, an AF mechanism
having an AF moving platform, and at least a Hall sensor or
position encoder; wherein the said OIS mechanism is capable of
moving the lens holder along a direction substantially
perpendicular to the optical axis; and the said AF mechanism is
capable of moving the AF moving platform along the optical axis;
wherein the said lens holder of OIS mechanism is coupled to the AF
moving platform via a plurality of wires; wherein the Hall sensor
or position encoder is used to sense the lens position along the
optical axis and/or the position on a plane substantially
perpendicular to the optical axis.
FIG.8a shows another aspect of the OIS mechanism 16. Except the
wires 18 which are used to connect the lens holder 52 to the AF
moving platform 14, there are no other portions which are
connecting the lens holder 52 to the AF moving platform 14.
Therefore, the lens holder 52 of the OIS mechanism 16 can be
suspending in the air via the plurality of wires 18. As shown in
FIG. 8b, a gap 92 may be formed between the stiffening member 82
and lens holder 52. The stiffening member 82 is used to connect the
slidable guide members to enhance the rigidity of the AF moving
platform. In some embodiment, the stiffening member 82 is an
individual component. There will also be another gap 94 between the
bottom surface of the lens holder 52 and the upper surface of the
base 24 of AF moving platform 14.
In another embodiment as shown in FIGS. 8b and 8c, a viscous liquid
96 can be applied to the gaps 92, 94 to fill in the space of the
gaps 92, 94. The viscous liquid 96 can be either fill in one of the
gaps or both of the gaps. The viscous liquid 96 can be either a big
drop of that liquid or a plurality of smaller drops of the viscous
liquid 96.
FIGS. 8d and 8e show another embodiment, in which a plurality of
pits 98 may be formed on the bottom surface of the stiffening
member 82 and/or the upper surface of the lens holder 52. It can be
a one-side pit structure in which only one of stiffening member 82
and lens holder 52 has the pits 98 and the other one may be a flat
surface. The pits 98 on one surface can be pairing with pits on an
opposing surface to form a small cavity 99 which can be used to
hold the viscous liquid 96. The so-formed cavity will be more
efficient to hold the viscous liquid 96 rather than the gap shown
in FIGS. 8b and 8c. The viscous liquid is used to enhance the
mechanical rigidity of the lens driving apparatus along the optical
axis.
FIGS. 9a-i shows another embodiment of a miniature lens driving
apparatus. A plurality of leaf springs 100, 100' may be adopted as
shown in FIG. 9a and FIG. 9b. One end 103 of each leaf spring 100
can be firmly attached to the base 24 of the AF mechanism 12 while
another end 101 of each leaf spring 100 can be firmly attached to
the AF moving platform 14. All the leaf springs 100 may be
substantially lying in a same plane which is substantially
perpendicular to the optical axis. All leaf springs 100 can be
divided into three zones: moving end 101 fixed end 103, and spring
arm 105. The moving end 101 can be attached to the lens holder 52
while the fixed end 103 can be attached to the base 24. The spring
arm 105 is the portion where the leaf spring 100, 100' deforms to
generate elastic force. FIG. 9c shows another embodiment of the
leaf spring 102. The fixed ends 102' of the spring are all
connected into one piece as shown in the drawing (FIG. 9c).
Therefore, a plurality of leaf springs becomes a single leaf
spring.
FIGS. 9d and 9e show other embodiments of the leaf spring 100',
106. The moving end 101' can be attached to the lens holder 52
while the fixed end 103' can be attached to the base 24. The spring
arm 105' is the portion where the leaf spring 100, 100' deforms to
generate elastic force. Various patterns of leaf spring can be
adopted. Besides leaf spring, many other types of spring can also
be adopted for the same function. Such spring could be but not
limited to helix spring, elastic film, etc. FIGS. 9f and 9g are
enlarged views of the wires 18' and 18'' shown in FIG. 9a
respectively. FIGS. 9h and 9i disclose another embodiment of an AF
moving platform 114, which may have a wire coupling member 156
mounted at the lower end of the moving platform 114. At least a
wire will be connecting the lens holder or upper wire coupling
member to AF moving platform via the lower wire coupling member.
Moreover, the stiffening member 82 may be integrated into the AF
moving platform 114 to form an integrated stiffener 182.
While the miniature lens driving apparatus has been shown and
described with particular references to a number of preferred
embodiments thereof, it should be noted that various other changes
or modifications may be made without departing from the scope of
the appended claims.
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